「複雑 (ふくざつ)」 means something is complicated or intricate, having many parts that make it difficult to understand or solve. It's used for complex systems, problems, or situations where simplicity is lacking, often requiring careful thought. For example: この問題はとても複雑で、解決が難しいです。(This problem is very complex and difficult to solve.)

物事の仕組みや状況が込み入っていて、理解したり解決したりするのが難しいこと。多くの要素が絡み合っています。